Fusion of spinal vertebrae is often necessary to relieve debilitating pain or correct a deformity. Lumbar, thoracic and cervical spinal fusions are often prescribed for patients suffering from degenerative disk disease (whose symptoms include neck, chest, or back pain of discogenic or spondylotic origin with degeneration of the disk or surrounding structures confirmed by patient history and radiographic studies), trauma (including fractures), tumors, deformity (indicated by kyphosis, lordosis, or scoliosis) pseudoarthrosis, and/or failed previous fusions.
Spinal surgical fusion is the process of bringing together two or more vertebrae under conditions whereby the vertebrae fuse together to form a unitary member of the spinal column. When vertebrae are fused, e.g., with bone grafts, graft extenders, or interbody spacers such as interbody cages or boxes (collectively termed “grafts” herein), it is desirable to stabilize the fused vertebrae using apparati such as a plates, cages, or screws to fixate one or more lumbar, thoracic, or cervical vertebra to another to promote fusion across motion segments. In carrying out the procedure, the members must be brought together under conditions that are critically controlled to prevent infection, maintain alignment of opposing members, and allow for the stress in the bone that is generated as the healing process matures. Immobilization is an important requirement during this healing process.
In addition to stabilization, osteogenic, osteoconductive and/or osteoinductive substances are often applied to surrounding areas to promote bone growth. An example of such a substance is the Trinity™ multipotential cellular bone matrix which has osteogenic, osteoconductive and/or osteoinductive properties. The Trinity™ matrix consists of viable adult stem cells, which are osteogenic cells. The Trinity™ matrix also has osteoinductive signals and provides an osteoconductive matrix which can be used in a wide variety of surgical applications where filling a bone void or stimulating bone growth is required. The Trinity™ matrix is but one osteogenic substance on the market and is mentioned for exemplary purposes only. Much like an autograft, the Trinity™ matrix has the three key bone growth properties: osteogenic cells, osteoinductive signals, and an osteoconductive scaffold, but other products currently on the market and many that are in development may prove to be as good or even better using similar or newer biologic principles. The device described is designed to have the flexibility to be used by multiple types of biologic products
A universal problem with the use of osteogenic biologics is handling. The substances come in prepacked sizes and amounts. Therefore, it is difficult to obtain the exact amount of the substances actually needed, and a surgeon will often find himself/herself with either too much or too little. Given the relatively high cost of these substances, even a small amount of wasted material per patient becomes a major cost factor to patients, hospitals, and benefit providers. Another difficulty exists with the application and diffusion of the substance. The osteogenic substances are placed directly in the body in the area of surgical exposure where bone growth is desired. A considerable amount of the substance will consistently diffuse away from the initial site of application into the adjacent structures of the body, then be absorbed by surrounding muscle, or otherwise become dislodged or transplanted, and hence will be wasted and not produce the desired effect. Additionally, because the substances are not generally moldable and/or adherent and paste-like, it is difficult to apply them into small spaces, such as between vertebrae and expect the substance to be retained in that area. Inevitably, when inserting the substance between vertebrae, a considerable amount is scraped off during insertion and remains on the outer surface of the vertebrae, rather than between them in the space to be fused.
The recent trend in spine surgery are minimally invasive surgical (MIS) techniques which seems to parallel the evolution of interventional vascular and cardiac technology, arthroscopy for joint disorders, and laparoscopic techniques for general and gynecologic procedures. This is true for lumbar fusions using MIS techniques, such as XLIF, TLIF, or PLIF approaches. Minimally invasive approaches to the spine are rapidly becoming more common and have many positive features including: shorter operating room times; less blood loss; less disruption of tissue; and shorter recovery times. One of the criticisms of the MIS has been that these techniques do not allow for incorporation of effective posterior-lateral graft material, such as a Trinity™ or other osteogenic, osteoconductive, and/or osteoinductive biologic materials. While the hardware for minimally invasive surgeries (MIS) is rapidly expanding, the optimal use of biologics in MIS has not been as actively pursued. Therefore, while smaller incisions reduce recovery time, the rate of vertebral fusion has been reported to also be reduced due to the absence of an optimal way to deliver proper graft material.
It is therefore an object of the present invention to provide a device, system, and method for the application of an osteogenic, osteoconductive and/or osteoinductive biologic material to target sites in the lumbar, thoracic and cervical spine.